Roller for uniform production of pressure



June 25, 1968 H. BUYSCH ROLLER FOR UNIFORM PRODUCTION OF PRESSURE Filed April 21, 1966 ii Ii W ATTORNEY United States Patent 4 Claims. cr. 29-110 ABSTRACT OF THE DISCLOSURE The present disclosure sets forth a high pressure roller having a base cylinder with end shaft mounts, having an outer shell spaced therefrom connected thereto by means of spaced studs which are welded to the outer shell and have extensions into recesses in the base cylinder. The outer shell is encircled by a cylinder of hard or soft rubher or other suitable material.

The present invention relates to rollers for producing uniform pressure, particularly in the treatment of fiat materials, such as webs of woven, knitted, matted textile fibers and it also relates as a less preferred application to other types of mats or webs.

Where high pressure rollers are used for calenders, padders and similar roller equipment, the web of textile or other material is to be treated with a pressure uniform over the entire width of the roller.

Frequently, the pressure per square inch amounts to several tons or kilos on a relatively small area and the rollers, even though of resistant material or treated steel, tend to sag with the pressure decreasing toward the center of the roller.

It has been attempted to correct this sag of the rollers by varying the shape of the roller or by a crossing arrangement. In addition, it has been attempted to prevent the sag by supporting members distributed over the width of the roller which will tend to brace the roller over the length thereof to overcome any sag or undesirable bending or flexing thereof.

It has also been proposed to correct the sag by giving a slight barrel shape to the periphery of the roller, but such shaping can only be designed for a specific pressure.

Another proposal has been to develop the ends of the rollers as cantilever structures, and such a roller as compared with a rigid or solid wall center will achieve an elasticity toward the journal ends intended to assure a uniform pressure over the entire length or width of the roller. However, this cannot be readily matched to varying pressures.

Similar difiiculties have already been experienced with squeezing rollers or pressure rollers by which water or other liquids or fluids are to be expressed from webs of woven, knitted or matted materials, particularly where the axes are not exactly parallel but have a slightly crisscross arrangement. In such arrangement, the distance between axes in the center of the rollers is smaller than at the journal ends and any sagging in the center will tend to equalize the distance between the axes over the length of the rollers.

With such an arrangement to equalize different amounts of sag or different operating pressure, the angles of crossing of the axes must be correspondingly adjustable.

A criss-crossing of the axes usually has a disadvantageous eifect upon linear feeding and removal of the web of material.

Still further objects and advantages will appear in the more detailed description set forth below, it being understood, however, that this more detailed description is 3,389,448 Patented June 25, 1968 ice given by way of illustration and explanation only and not by way of limitation, since various changes therein may be made by those skilled in the art without departing from the scope and spirit of the present invention.

It has further been proposed to support the rollers over their entire length by separate supporting rollers, but these constructions increase the weight of the construction and greatly increase the cost, and create shortened life periods due to increased wear at the points of support. This is particularly so with rubber or plastic coated rollers.

If the rollers are made hollow and the support is placed interiorly, difiicult constructions are required readily susceptible to derangement and breakdown. Where the inside of the rollers is provided with a pressure chamber to receive fluid under pressure to counteract the sagging of the roller, considerable maintenance is required and the cost is greatly increased.

Where interiorly of a hollow roller a supporting disc is employed, carried by a separate journal which is stationary or rotates with the roller, the cost is greatly irrcreased and most satisfactory results are not attained.

Lastly, where the sag is counteracted by making the wall of a shell of a hollow roller of increased thickness towards the center of the roller, here, again, the compen sation is only accurate for a certain predetermined pressure and there is very little tolerance for variations of pressure.

The object of the present invention is to create by means of a relatively low cost, uncomplicated arrangement, a pressure roller or pressure rollers which will have limited or inconsequential or inappreciable sag under widely varying operating pressures, without special maintenance or unduly costly accessories and substantial increase in weight.

In the preferred form of the present invention, the roller is provided with a hollow core which receives the journals and with a roller shell which is supported at individual points on the core and otherwise surrounds the area with clearance.

The roller shell is desirably supported on the core which passes through the shell from the outside.

The same is also true of known squeezing apparatus in which the axes of a pair of rollers are not parallel, but arranged slightly criss-cross, so that the distance between axes in the center of the rollers is smaller than at the journal ends, and that as a result of the sag in the center, an equalizing of the distance between the axes over the length of the rollers results. In order, with such an arrangement, to equalize different sags or different operating pressures, the angle of crossing of the axes must be correspondingly adjustable. A criss-crossing of the axes, however, has an unfavorable effect on the linear feeding and removal of the web of material. It has therefore already been proposed to support the rollers over their width by means of supporting rolls directly or over a supporting roller. These arrangements, due to the many supports, lead to heavy constructions, at a correspondingly high cost. In addition to this, the rollers are subjected to increased wear at the points of support, particularly in the case of rubber-covered or plastic-coated rollers.

Finally, the support against sagging has also been shifted into the inside of the rollers which are made hollow. In addition to complicated designs which are susceptible to breakdown and in which the inside of the roller is provided with pressure chambers to receive fluid which, under pressure, counteracts the sagging of the roller (German Patent 1,155,750), a central supporting within. the inside of the roller by a supporting disc which is borne by the journal and is stationary or rotates with it has also 3 been proposed (German Petty Patent 1,883,014). The sag is counteracted by the fact that the wall of the shell of the roller becomes thicker inwards towards the center of the roller. In this way, however, even this roller can only compensate for the sag which corresponds to a given pressing pressure.

The object of the present invention is to create by simple means a roller, the sag of which is entirely insignificant for all practical operation, even under different operating pressures. The invention proceeds for this purpose from a roller which consists of a preferably hollow core which receives the journals and of a roller shell which is supported at individual points on said core and otherwise surrounds the core, with some clearance. In accordance with the invention, the roller shell is supported on the core by supporting bodies which pass through the shell from the outside.

This type of support has the advantage for the operation of the roller that there is no relative movement which favors wear between the core and the shell. However, the development in accordance with the invention is also advantageous for the manufacture of the roller, since, for the same reason, there are not required between the roller shell and core any bearings which presuppose a precision fit.

With respect to the arrangement of the supporting bodies, the invention makes use of a length ratio knoWn, per se, in connection With supports and provides that the supporting bodies are uniformly distributed over two circumferential lines each at a distance of about A the width of the roller from the ends of the roller. In this way, the maximum sag which normally occurs in the center of the roller is divided up into two eccentric symmetrical sags, the sum of which is considerably less than the central maximum sag in the traditional arrangement of the support, for instance, by the end discs of the rollers.

The manufacture of the roller of the invention is particularly simplified when the supporting members consist of threaded bolts which are screwed in the shell of the roller and the unthreaded cylindrical end of which rests in blind bore holes in the core of the roller.

By means of the bolts which can be screwed into the shell of the roller, there can be obtained by very simple means a firm clamping of the shell of the roller with respect to the core. Precision-fitting work is limited to the blind bore holes in the core.

In order that the supporting bodies which have been introduced cannot subsequently become loose, the invention proposes that the supporting body be welded to the shell of the roller. The roller in accordance with the invention, after insertion of the supporting bodies, can be covered in known manner with hard rubber and/ or soft rubber.

One embodiment of a roller of the invention is shown schematically in cross-section in the drawing.

1 is the hollow roller core which bears at its ends journal pins 2 and 3. A shell 4 surrounds the roller core 1 with some clearance. The shell 4 is provided uniformly over two circumferential lines with threaded bore holes 5, into which there are screwed bolts 6, the cylindrical end 7 of which rests in blind bore holes 8 of the core of the roller. The threaded bolts 6 are firmly connected to the roller shell 4 by weld seams 9. The outward facing end surfaces of the bolts 6, as well as the weld seams 9, are so machined that they are flush with the service of the roller shell 4. Depending on the purpose of use of the roller of the invention, the roller shell 4 is provided with a covering 10 of hard and/ or soft rubber or of some other material which is adapted to the specific requirements.

What is claimed is:

1. In a machine for applying uniform high pressure to webs of textile fabrics selected from the group consisting of calenders and padders, an elongated, small diameter hollow roller consisting of an interior hollow heavy core cylinder having a plurality of spaced recesses on its exterior face, an encompassing encircling light roller shell surrounding said core cylinder with small clearance, and an exterior covering of cylindrical contact material closely contacting and encircling the surface of the roller shell, said roller shell having a plurality of openings therein positioned at and coinciding with said spaced recesses and mounting means placed in said openings and recesses and extending through the roller shell and into said recesses to support said roller shell on said core cylinder.

2. The machine of claim 1, the mounting means having threads thereon uniformly distributed over the surface of said roller shell and core cylinder and being threaded into said plurality of openings.

3. The machine of claim 1, said mounting means consisting of threaded bolts screwed into the roller shell and extending into the spaced recesses and fastened to the roller shell.

4. The machine of claim 1, wherein said exterior covering is made of rubber.

References Cited UNITED STATES PATENTS 2,595,041 4/1952 Wright 29-110 2,952,889 9/1960 Hanssen 29-116 X FOREIGN PATENTS 11,583 2/1903 Norway.

BILLY I. WILHITE, Primary Examiner. 

